Kilowatts to amps
Multiply kilowatts by 1 000 to get watts, then divide by the voltage. A 7.2 kW EV charger on 240 V draws 30 A.
Kilowatts to amps calculator
AC single-phase, power factor 1 · change under Options
Resistive loads (heaters, kettles, incandescent bulbs) have power factor 1. Motors are often 0.8–0.9. For three-phase, enter the line-to-line voltage (for example 208, 400 or 480 V).
How it’s calculated
1 W = 1 V × 1 A · 1 kW = 1 000 W
I (A) = P (kW) × 1000 ÷ (V × PF)
Step by step
- Convert to watts: 7.2 kW × 1 000 = 7,200 W.
- Divide: 7,200 W ÷ 120 V = 60 A.
Kilowatts to amps table
| kW | 12 V | 120 V | 230 V | 240 V |
|---|---|---|---|---|
| 1 kW | 83.333 A | 8.3333 A | 4.3478 A | 4.1667 A |
| 2 kW | 166.67 A | 16.667 A | 8.6957 A | 8.3333 A |
| 3 kW | 250 A | 25 A | 13.043 A | 12.5 A |
| 5 kW | 416.67 A | 41.667 A | 21.739 A | 20.833 A |
| 7.2 kW | 600 A | 60 A | 31.304 A | 30 A |
| 10 kW | 833.33 A | 83.333 A | 43.478 A | 41.667 A |
| 15 kW | 1,250 A | 125 A | 65.217 A | 62.5 A |
| 20 kW | 1,666.7 A | 166.67 A | 86.957 A | 83.333 A |
| 50 kW | 4,166.7 A | 416.67 A | 217.39 A | 208.33 A |
Table uses the circuit type and power factor set under Options (AC single-phase, PF 1).
FAQ
Industrial loads are often three-phase: open Options, choose “AC three-phase”, and enter the line-to-line voltage and power factor.
How do I convert kW to amps?
Amps = kW × 1 000 ÷ volts for DC or single-phase AC with power factor 1. For three-phase: amps = kW × 1 000 ÷ (√3 × volts × PF).
How many amps is 10 kW at 400 V three-phase?
With power factor 0.9: 10 000 ÷ (1.7321 × 400 × 0.9) = 16.04 A per phase.
What voltage should I use?
Use the voltage the device runs on: 120 V for standard North American outlets, 230 V in the UK, Europe and much of the world, 240 V for large North American appliances, and 12 V for car and RV electrics.
What is power factor?
Power factor (PF) is the share of AC current that does useful work. Resistive loads such as heaters and incandescent bulbs have PF 1. Motors and some power supplies are lower, often 0.8 to 0.95, which means they draw more amps for the same watts. Set it under Options.
What about three-phase power?
For a balanced three-phase load, I = P ÷ (√3 × V × PF), where V is the line-to-line voltage. Choose “AC three-phase” under Options.
Can I size a breaker or wire with this?
Unitglide gives the current the load draws. Breakers and wiring must follow your local electrical code, which adds safety margins (for example 80% continuous load rules), so check with a licensed electrician.
Sources
- NIST SP 811 and the SI Brochure (BIPM): 1 W = 1 V × 1 A: P = V × I for DC; P = V × I × PF for single-phase AC; P = √3 × V × I × PF for three-phase AC.
Checked by Unitglide on 2026-10-27.